Despite being the most common way to protect computers and sensitive data, passwords are a terrible security solution. So scientists at Hong Kong Baptist University are teaching computers to read a user’s lips as a far more secure method of biometric security.

Choosing a password that’s both unique enough to be secure and simple enough to remember is getting harder and harder. That’s why many laptops and smartphones include fingerprint readers for an added layer of biometric security. However, faking fingerprints is easier than you might think, so Cheung Yiu-ming, a professor at the university’s computer science department, wants computers and smartphones to use the unique movements of a user’s lips while they say their password as another layer of authentication.

The feature would only work on devices with a user-facing camera, but it would offer advantages over voice-based authentication, which can be tripped up by background noise and other sounds, is often language-specific, and simply doesn’t work for those with a speech impairment. The lip-reading approach, which tracks lip shape, movement, and even texture, could be used almost anywhere. It would also be virtually impossible for someone else to mimic, as those qualities are unique to every user.

The new approach would still require a user to remember a spoken passphrase, which would be hard to keep secret given this technology is proposed for use with cash machines and other machines that reside in very public places. But even if someone overhears what you’ve said, it should be impossible for them to fool a device—unless they happen to be your twin [Hong Kong Baptist University via New Atlas]